Locking for screw threaded male parts



hvvz/v-ran D- NIELD par 'JOMM 8.15am

ATTORNEY March 13, 1945. D. NlELD LOOKING FOR SCREW THREADED MALE MEMBERS Filed March 4, 1944 FIG '5.

Patented Mar. 13, 1945 LOOKING FOR SCREW THREADED MALE PARTS Douglas Nield, Dinas Powls, Wales Application March 4,1944, Serial No. 524,994 In Great Britain March 27, 1943 1 Claim.

This invention comprises improvements in the locking of screw threaded male parts and refers more particularly to set screws and bolts. The object of this invention is to prevent the set screw or bolt unscrewing with vibration or strain.

Referring to the drawings-.-

Figure 1 is an elevation, partly in section of a set screw according to this invention.

Figure 2 shows an elevation, partly in section, of another type of set screw according to this invention, whilst,

Figure 3 is an elevation partly in section, of a bolt according to this invention.

In carrying the present invention into practice, as shown upon the accompanying drawing, at Figure 1, the set screw 4 has an hexagonal head 5. These portions of the set screw are coaxially.

bored to accommodate a rotatable core 6, to the lower end of which is secured or formed the threaded extension I, which in effect is an extension of the threaded part 4 of the set screw. The thread on this part 1 being a continuation of the thread on the part 1. I

To the upper end of the core 6 is secured by welding or in any other suitable manner the hexagonal headed part 8 which is adapted to coincide with the head 5 of the set pin, so that a spanner or the like can be fitted onto the heads 5 and 8 at the same time for screwing the stud into position or for withdrawing same.

In order to indicate that the thread extension I is in its correct relation to the main part 4 of the stud an indicating mark 9 is provided on the two heads 5 and 8. When it is desired to insert or withdraw the stud, these indicating marks 9 are brought into alignment.

To look the stud after it has been placed in position, the screwed extension I is given a partial turn in either direction, by means of the head 8, so that the thread on the extension 1 is thrown out of pitch with the thread on the part 4 .of the stud, thus locking the stud in position and preventing same screwing out of the screwed hole in which it has been positioned.

Figure 2 of the drawing shows a threaded stud, having a countersunk head ID, the main screwed part. II of the stud, has an extension I! to which is secured the core l3 positioned in and rotatable in the coaxial bore of the stud. The upper end of the core I3 is provided with the head which is countersunk into the head 10.

The heads l and H are provided with a. slot I! which indicates, when the slot I is in alignment in the heads l0 and I, that the screw thread on threaded part and a the main part H and extension l2 oi the stud is in continuity for the insertion or withdrawal of the stud.

The operation for locking the stud in position is similar to that described with reference to Figure 1, except that a screw driver would be used in the slot [5 for rotating the stud.

Figure 3 shows the application of this invention to a bolt, in which the shank l8 of the bolt is provided with a hexagonal head I! and a screwed part I8. The shank l6 and head 11 of the bolt are bored out concentrically.

An extension I9 of the screwed part l8 of the bolt is provided, which extension l9 has a core 20 formed integral therewith or secured thereto. in any suitable manner, which extends the length of the bolt and head H. To the core 20 is attached by welding or other suitable means the hexagonal part 2| which coincides with the hexagonal bolt head H.

The thread on the extension I9 is adapted to form a continuity of the thread on the screwed part 18 of the bolt and to indicate when the two parts of the thread are in continuity, the bolt head l1 and the part 2| are provided with an indicating slot or marking 22, which are brought into alignment with the continuity of the screw thread on the two parts l8 and I9 are required.

It will be seen, that when the nut 23 is screwed onto the shank it of the bolt, to lock the bolt to the nut 23, a partial rotation in either direction of the hexagonal part 2| will throw the pitch of the thread on the extension l9 out of relation with the pitch of the thread on the screwed part as of the bolt and thus lock the bolt to the nut 23.

It will be noted that variations may be made particularly with the method of attachment of the parts 8, l9 and also with the methods provided for rotating these parts, without affecting the scope of the claim.

I claim:

Improvements in the locking of screwed male parts, comprising in combination a main threaded part having a coaxial bore therein, a separate threaded extension of said main threaded part forming a continuity thereof, a core forming an extension of said separate threaded part and being positioned in the coaxial bore of the main headed member attached to said core for rotating the separate threaded part to throw the thread on same out of pitch with the thread on the main threaded part to lock the screwed male part in position.

DOUGLAS NIELD. 

